Support beam with a steel core frame

ABSTRACT

The present invention relates to support beams in an insulated floor of a refrigerated trailer.

I. FIELD OF THE INVENTION

The present invention relates to support beams in an insulated floor.

II. BACKGROUND OF THE INVENTION

A typical trailer, for example, with a length ranging from 20 to 60 feet, has the shape of a cuboid. The cuboid has two side walls and two end walls, one of which is usually provided with a lockable opening or doors.

An insulated floor for refrigerated trailers generally has an upper floor layer and a lower floor layer. An insulating layer is located between the upper floor layer and the lower floor layer.

Several support beams are located between the upper floor layer and the lower floor layer in the longitudinal direction of the floor plate. The support beams have a substantially larger deformation resistance than insulating layer. Accordingly, load acting upon the upper floor layer is entirely received by the support beams. The insulating layer does not have to carry any load. Thus, it is possible to dimension the insulating layer exclusively in consideration of the insulating effect. The load-carrying capacity plays practically no role. Accordingly, the insulating layer can be made relatively soft and with a higher share of air, so that its insulating effect is optimized. One example is an insulating layer made of polyurethane foam.

Support beams are typically made from wood or plastics. These support beams, however, absorb moisture and gradually lose the load-bearing capacity. Also, the sandwich of upper floor layer, insulating layer and lower floor layer is susceptible to delamination. If the bonding between the layers fails, the rigidity and the strength of the floor are substantially impaired. This can be caused by cracked support beams and/or detached support beams from the upper or lower floor layer, and are frequent reasons for repair work on known trailers.

Therefore, an improved support beam for an insulated floor is desirable.

III. SUMMARY OF THE INVENTION

Certain embodiments are based on the task of improving support beams in an insulated floor of a refrigerated trailer. With a trailer floor as mentioned in the introduction, this task is solved in that a steel core frame is inserted in each support beam.

In certain embodiments, a support beam is made of commodity plastics.

In certain embodiments, a steel core frame comprises a flat upper surface and two flat side walls elongated in the longitudinal direction of the support beam.

In certain embodiments, a steel core frame comprises a flat lower surface and two flat side walls elongated in the longitudinal direction of the support beam.

In certain embodiments, a steel core frame comprises a flat surface elongated in the longitudinal direction of the support beam.

In certain embodiments, a support beam with a steel core frame has guide holes for screws on the top surface, each hole entering the steel core frame. The screws can connect the lower flat side of the upper floor layer and the support beam.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the present invention will become apparent from the following detailed description thereof when taken in conjunction with the appended drawings in which:

[FIG. 1] FIG. 1 is a perspective rear view of a refrigerated trainer with an insulated floor.

[FIG. 2] FIG. 2 is a perspective top and longitudinal side view of an insulated floor of a refrigerated trailer with I-shape support beams consistent with one embodiment of invention;

[FIG. 3A] FIG. 3A is a sectional view of an I-shape support beam consistent with one embodiment of the invention and of illustrating a screw being inserted into the I-shape support beam;

[FIG. 3B] FIG. 3B is a perspective view of an I-shape support beam consistent with one embodiment of the invention and of illustrating holes on the upper surface of the I-shape support beam;

[FIG. 4A] FIG. 4A is a sectional view of an H-shape support beam consistent with one embodiment of the invention and of illustrating a screw being inserted into the H-shape support beam;

[FIG. 4B] FIG. 4B is a perspective view of an H-shape support beam consistent with one embodiment of the invention of illustrating holes on the upper surface of the H-shape support beam;

[FIG. 5A] FIG. 5A is a sectional view of a rectangular support beam consistent with one embodiment of the invention and of illustrating a screw being inserted into the rectangular support beam.

[FIG. 5B] FIG. 5B is a perspective view of a rectangular support beam consistent with one embodiment of the invention of illustrating holes on the upper surface of the rectangular support beam.

V. DETAILED DESCRIPTION OF THE INVENTION

A typical trailer, for example with a length of 20 feet or 60 feet, has the shape of a cuboid. The cuboid has two side walls and two end walls, one of which is usually provided with a lockable opening or doors.

Currently, many shippers utilize refrigerated and/or insulated trailers (such as reefer trailers) to transport items that require the maintenance of specified temperatures during transit. These trailers typically have an insulated floor (1) comprising an upper floor layer (2), a lower floor layer (4), an intermediate insulating layer (3) and support beams (8, 9, 10) being located between upper floor layer (2) and the lower floor layer (4).

The upper floor layer comprises a plate, which is in some cases assembled of several sections that are joined with each other at welding points or by interlocking edges.

An upper floor layer particularly suited for refrigerated trailers or other carriers is generally made up of interconnecting panes, each of which is formed with a plurality of parallel-spaced inverted U-shaped channel members. In another common configuration of an upper floor layer is made up of a number of interconnecting panels, each of which consists of a generally flat base from which a plurality of parallel-spaced T-shaped members extend upwardly, the horizontal top flanges of the members all lying in the same plane to support the goods being carried. In another configuration, an upper floor layer is formed of a plurality of interlinked panels, each panel being integrally formed with at least one longitudinally extending T-shaped member and at least one parallel, longitudinally extending inverted U-shaped channel. Various combinations of T-shaped members and U-shaped channels are available.

An upper floor layer is typically extruded from aluminum these days.

On the other hand, a lower floor layer is typically made from fiber-reinforced plastic.

An insulating layer is located between the upper floor layer and the lower floor layer, the insulating layer being typically made of polyurethane foam.

Several support beams are located between the upper floor layer and the lower floor layer in the longitudinal direction of the floor plate. Various shapes of the support beams are available such as I-beams, H-beams or rectangular beams. Generally, H-beam's width of the flange is equal to or more than the height of the cross section. On the other hand, I-beam's height of the cross section is higher than the width of the flange. In the case of I-beams, the width of one flange can be shorter or longer than the other flange.

The support beams have a substantially larger deformation resistance than insulating layer. Accordingly, load acting upon the upper floor layer is entirely received by the support beams. The insulating layer does not have to carry any load. Thus, it is possible to dimension the insulating layer exclusively in consideration of the insulating effect. The load-carrying capacity plays practically no role. Accordingly, the insulating layer can be made relatively soft and with a higher share of air, so that its insulating effect is optimized. One example is an insulating layer made of polyurethane foam.

Each support beam is generally connected to the lower floor layer by means of adhesive. Once support beams are connected to the lower floor layer, the upper floor layer is mounted and the support beams are generally connected the lower flat side of the upper floor layer, its configuration being either inverted U-shaped or T-shaped, by means of screws. In certain embodiments, a support beam with a steel core frame has guide holes for screws on the top surface, each hole entering the steel core frame. The screws can connect the lower flat side of the upper floor layer and the support beam.

Support beams, are typically made from wood or plastics. Commodity plastics are more commonly used to make the support beams than engineering plastics because commodity plastics exhibit relatively low mechanical properties and are of low cost. One example of commodity plastics is polypropylene. The other examples of commodity plastics are polyethylene and polyvinylchloride.

Support beams made from wood provides light weight and higher strength than commodity plastics but suffers the disadvantage that wood is able to absorb moisture from condensation, resulting the loss of load-bearing capacity.

Support beams made from commodity plastics does not absorb moisture as much as ones made from wood but provide lesser load-bearing capacity. Typically, talc is added to the plastics as a cost-effective filler in order to improve load-bearing capacity. However, because of surplus stiffness, the support beams made from commodity plastics with talc tend to break apart more easily under heavy stress.

On the other hand, support beams made from engineering plastics hold improved load-bearing capacity which is comparable to the support beams made from wood but considerably lack cost-competitiveness.

In many cases, screws that are connecting the support beams and upper floor layer become loose over time because, if a screw is constantly subject to vibration of a moving vehicle, the original thread pattern of the screw in the wood or plastic support beam wears away eventually and no longer maintains the thread pattern from the original installation.

In the known constructions, the sandwich of upper floor layer, insulating layer and lower floor layer is susceptible to delamination. If the bonding between the layers fails, the rigidity and the strength of the floor are substantially impaired. This can be caused by cracked support beams and/or loosen screws from the support beams and are frequent reasons for repair work on known trailers.

The present invention has many advantages over the prior art. Firstly, since internal steel core frame supplements strength, the support beam can be made from more cost-effective and flexible commodity plastics resulting higher load-bearing capacity and less breakage upon high pressure. Moreover, because screws will penetrate the internal steel core frame when it connects the support beam and the upper floor layer, the internal steel core will provide sufficient friction to keep a screw tight without being worn down.

Apparatus consistent with the present invention will now be described with respect to a support beam for an insulated floor of a refrigerated trailer.

Referring firstly to FIG. 1, an insulated floor of an refrigerated trailer (1) consists of an upper floor layer (2), a lower floor layer (4), an intermediate insulating layer (3) and support beams (8, 9, 10). One example is an I-shape support beam (8) as shown in FIG. 3. Such support beam was previously made of wood and is now commonly made of commodity plastics or commodity plastics with reinforcing additive, such as, talc.

As shown in FIG. 2, each support beam (8) is generally connected to the lower floor layer (4) by means of adhesive, and the upper floor layer (2) is connected to the lower flat side of the upper floor layer (2B) by means of screws (7).

As shown in FIGS. 3A-5B, in one embodiment, a support beam includes an internal steel core frame (5) having a flat upper surface and two flat side walls (5) elongated in the longitudinal direction of the support beam. In certain embodiment, the steel core frame is 0.03 inches thick.

In certain embodiments, a steel core frame comprises a flat lower surface and two flat side walls elongated in the longitudinal direction of the support beam.

In certain embodiments, a steel core frame comprises only flat surface elongated in the longitudinal direction of the support beam.

Referring to FIGS. 4A and 4B, the support beam is H-shape in one implementation.

Referring to FIGS. 5A and 5B, the support beam is rectangular in one implementation.

As shown in FIGS. 3B, 4B and 5B, in one embodiment, a support beam with a steel core frame has guide holes (6) on the top surface for screws (7). The screws can connect the lower flat side of the upper floor layer and the support beam.

It should be understood that the implementations described above may be used both to create a new support beam for an insulated floor and to modify an existing support beam. While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention. 

What is claimed is:
 1. A support beam comprising: a beam having a longitudinal axis, a top and bottom surface; and at least one internal steel core frame inserted into the beam.
 2. A support beam according to claim 1 wherein the internal steel core frame comprises a flat surface with two flat side walls elongated along the longitudinal axis of said beam.
 3. A support beam according to claim 1 wherein the internal steel core frame comprises only a flat surface elongated along the longitudinal axis of said beam.
 4. A support beam according to claim 1 further comprising at least one guide hole for screws on the upper surface, lower surface or both upper and lower surfaces of said beam.
 5. A support beam according to claim 1 wherein the internal steel core frame is inserted in the upper flange section of said beam.
 6. A support beam according to claim 1 wherein the internal steel core frame is inserted in the lower flange section of said beam.
 7. A support beam according to claim 1 wherein the internal steel core frames are inserted in the upper flange section and the lower flange section of said beam.
 8. A support beam according to claim 1 is an I-shape beam wherein the height of the cross section is higher than the width of the flange of said beam.
 9. A support beam according to claim 1 is an H-shape beam wherein the width of the flange is equal ,to or more than the height of the cross section.
 10. A support beam according to claim 1 is a rectangular shape beam.
 11. A support beam according to claim 1 is made of plastics. 